Strong



Dec. 15 1925' 1,565,771

P. E. ARMSTRONG PROCESS OF MAKING TUBULAR BODIES Filed Aug. 18, 1919 .WI' /V/ INMENTUR F/ZEflEME THU/V5.

fl TTURNEY' 4 for convenience, as sand.

Patented Dec. 15, 1925.

UNITED STATES I PERCY A. E. ARMSTRONG, OF LOUDON'VILLE, NEW YORK, ASSIGNOR TO LUDLUM STEEL PATENT OFFICE.

COMPANY, OF WATERVLIET, NEW YORK, A CORPORATION OF NEW JERSEY.

PROCESS OF MAKING TUBULAR BODIES;

Application filed August 18, 1919. Serial No. 318,253.

T 0 all whom it may concern:

Be it known that I, Pane-Y A. I). Ania- STRONG, a subject of the King of Great Britain, and residing at Loudonville, in the 6 county of Albany, State of New York, have invented certain new and useful Improve-' ments in Processes of Making Tubular Bodies, of which the following is a specification.

10 The present invention relates to the manufacture of tubular bodies. The invention will be described in connection with the production of hollow steel drill rod, but it is to be understood that it is applicable to production of other tubular bodies and that other materials may be used.

According to the present invention an ingot is cast around a tube. The bore of the tube serves to provide a bore for the cast ingot and this bore is utilized in the manu facture of the hollow drill rod or other tubular member. The tube is preferably of material which will be welded to the ingot in casting, so that a substantially integral ingot provided with a bore is obtained. 7 The bore in tlie tubular member is preferably protected during the casting and until the ingot hasycooled sufficiently so that any danger of melting the tube is passed. This may be accomplished in various ways, as for example, a current of gaseous or vaporous or liquid material, as

at v

. air, steam, water, etc., may be passed throu h the tube for withdrawing heat there rom, or the interior of the tube may be filled vwith a heat resisting material as finel divided dead burned magnesite, talc or t e like, which finely divided materials will be generally referred to hereinafter,

. After the ingot has been cast, it is treated for elongation and reduction of cross-section, as by hot rolling, with a core in place in the bore provided in the manner defil scribed. This core may be of various forms,

as for example a sand core may beused and when sand isprovided in the tube during the casting, the same sand may be or the core inthe further treatment. as rolling, for elongation. and rolling of used cross-section. If desired, the core may be put in-place after the ingot is cast, and in this case it becomes possible to smooth or H dress up the bore. This may be done in The ingot mold 10 maybe of any desired I form.

The customary separate top piece of clay or the like 11 may be used with the ingot.

mold, if desired. The tube 12 is supported in place in any desired way substantially centrally .of the ingot mold and the moltenmetal 13 is poured around it, becoming welded more or less strongly to the walls of the tube 12, during casting. Even if welding is not complete during casting it becomes substantially complete during subsequent working of the. material, as by rolling.

In making hollow drill rod of steel, such as high speed steel for example, the tube may advantageously be of steel of composition similar to the steel used for casting the ingot, but somewhat lower in carbon, and

consequently having a somewhat higher melting point. Such materials weld together well; the higher melting point of the tube material is useful in maintaining its tubular form during the casting operations and finally the carbon content is substantially equalized throughout the ingot and its bore lining by saturation, so that a substantially homogeneous product is obtained. The bore 14 of the tube 12 may be preserved in various ways. Heat may be withdrawn as by blowing air or steam through or by passing water through the bore or in various other ways. In the form shown in Fig. 1 finely'divided material 15, such as has been referred to as sand, is placed within the tube 12 and serves to keep the walls thereof suflicientlycool to prevent melting of the tube. The sand or other material may be taken out of the tube and the ingot bore so pjroduced may be smoothed or dressed up, as y drivin Va mandrel 16 therethrough, as indicated 1n Fig. 2, which shows the tube 12 welded to the cast ingot material13'. In

such case a new core is provided inany desired, however, material in place within the. tube during casting may be retained [herein to serve as a core during subsequent working, as by rolling or other like'operations. In Fig. 1 a metallic rod 17 is placed centrally in the core sand and the ends of the tube are sealed up, as by means of screw threaded plugs 18, 19, which serve to centralize the rod 17 and to retain the sand 15 in place. \Vhen screw threaded plugs are used they may be conveniently screwed up tight to keep the sand well compacted, but screw threads may be dispensed with, and plugs of nonmetallic materials, such as plugs of clay 01' thelike may be used if desired.

The ingot with its core, either put in the bore after the bored ingot is formed, or in place therein during the castin operation and thereafter, is treated with tie core for elongation and reduction of cross-section, as

by rolling, drawing or the like operations and the core material is thereafter withdrawn from the completed tubular body. If sand is used alone for the core it may be removed from the tubular body produced by suction or by blowing or the like, and where sand with the vcentral rod 17 is, used, the rolled drill rod is preferably broken or cut off at one or both ends and the rod 17 withdrawn after which the sand core can be removed. The rod 17 may be roughened or of various forms, so as to prevent the sand from caking unduly and also serving to dig up and loosen the sand durin the V removal of the rod,.or if desired, the fo llowing end ofthe rod, which goes through and comes out last, may be deformed to assist in loosening the sand asthe rod is drawn or driven out and various other types of cores-may be used as may be desired.

The drawings are for illustration and for affording an understanding of my invention only and not for limitation, and various changes and modifications may be resorted to within the scope of my claim.

I claim:

The process of making tubular bodies,

such,as hollow drill steel, which comprises casting an ingot of relatively high carbon steel about a tube of lower carbon steel having a higher melting point than the cast-- material, whereby welding and substantially carbon equalization of the two steels are secured at least in part, hot rolling the ingot with a core in said tube for elongation and reduction of cross section, whereby the Weld- PERCY A.-E. ARMSTRONG. 

